Dental flask



March 17, 1 3 c. FRITZEMWALLNEH DENTAL FLASK Filed May Patented Mar. 17, 1931 CONRAD FRITZENWALLNER, F CINCINNATI, OHIO DENTAL FLASK Application filed May 2,

My invention relates to dental plate flasks, and its object is to facilitate the closing and opening of such flasks. Other objects will appear in the course of the following description.

10 the line 2-2 of Fig. 1;

fas well as the general shape 0 =being substantially lfiasks of the prior art. The shape and size Fig.3 is a front elevation of the flask;

Fig. 4 is a rear elevation of the same; Fig. 5 is a detailplan view of the front portion of thetop cover;

Fig. 6 is a detail side elevation of the rear portion of the upper section; and

Figs. 7 and 8 are, respectively, detail plan views of a front portion and a rear portion of the lower section.

The lower section 1 has itsbottom 2 integral with its side walls 3, and the upper section 4 has its topcover 5 se arate; these,

the sections, the same as is found in of the flask are dictated by the shape and sizeof the dental plate to be molded, with fthe view of minimizing the amount of molding material, such as plaster, that must be 30' used, as well as to get the flask into a vulcanizer as small as possible in proportion to the size of the plate molded.

The lower section 1 has at its front, next to its upper rim, a forwardly extended pair ofribs 6, between which, set back from the front ends of the ribs, is a transverse bar portion 7 with a web 8 extending from its upper part back to the rim, leaving a recess ,9 under theweb between the bar portion 7 and the wall'3. At the back, this lower section 1 has the pair of lugslO and 11 extending back and so curved that their insides together with the adjacent portion of the wall 3 form a conical socket 12 with its diameter increasing upwardly; the lug being longer than the 1ug11 and the ends of the lugs being separated so that the wall of the socket thus formed. is not continuous,

but has aslot 13 opening backward and to one side, from top to bottom of the socket 12.

1928. Serial No. 274,507.

The upper section 4 has at its front, next to its lower rim, a forwardly extended hook 14 which, when the two sections 1 and 4 are brought toward their operative positions enters snugly between the ribs 6 of the lower section 1 to hook down around the bar portion 7 thereof. The end of this hook 14 is received in the recess 9 while the sections are inclined away from each other in the initial stages of bringing them together preparatory to swinging them together into closing relation, with the bearing of the hook 14 around the bar portion 7 as a pivot for this swinging. This snug fitting of the hook 14 between the ribs 6 establishes the front-to-rear alinement of the front parts of the two sections 1 and 4. At the back, the upper section 4 has a rearwardly projected lug 15 with an extension 16 downward past the lower rim of the section 4, which extension is so located and conically shaped that it will fit snugly into the conical socket 12 of the lower section 1 when the two sections 1 and 4 are brought completely together in operative relation to each other; this fitting completing, in conjunction with the fitting of the hook 14 at the front, the frontto-rear alinement of the two sections. Also, this conical extension 16 is so located with reference to the socket 12 as to cause the hook 14 to be pulled back firmly against the bar portion 7 when fitting firmly in the socket 12, thus establishing the transverse alinement of the two sections 1 and 4.

The lug 15 and its extension 16 have vertically through them a bearing opening in which a shaft 17 having on its bottom a radially extended catch 18, fixed to the shaft, and having at its top a head 19 bearing down on a washer 20 that bears on the top of the lug 15; this head holding the shaft up so that the catch 18 bears closely against the bottom of the extension 16 to swing under and bear tightly up against the bottom of the longer lug 10 of the lower section 1. This catch 18 is made narrow enough, in next to the shaft 17, to slip down through the slot 13 of the lower section socket 12 when swung around as in Fig. 6, as the sections 1 and 4 are swung together;

the outer end of the catch preferably being made wider, for pressure of the fingers of the operator, to swing the catch under the lug 10, thus firmly clamping the two sections 1 and 4 together. The tapering or conical formation of the socket 12 and extension 16 permits the extension to swing into the socket, and, bearing its front side against the front side of the socket, to pull the upper section 4 backward on the lower section 1, as the extension 16 is forced down into the socket. The result is that the two sections are properly alined without any special attention on the part of the operator;

and the clamping is effected by the very simple swinging of the catch 18 to one side. The Washer 20 may be made of material harder than that of the section 4 or of the shaft 17, so that the head 19 may be formed on the shaft by upsetting the end of the shaft; and wear may be taken up by additionally upsetting this head.

On its upper rim, the upper section 4 has at its front an upstanding lug 21 with a lateral extension 22 at its top; and at the back, on this rim, is an upstanding lug 23 the front sides 24 of which recede in both lateral directions from its middle and'also is undercut throughout these receding portions. The top cover 5 is a flat plate having in its rear edge a recess 25 into which the uppersection rear lug 23 fits, with theedges ,of the recess 25 slanted to engage snugly under and against the undercut sides of the lug 23, holding the rear part ofthe cover in alinement with the section 4.

The front edge of the top cover 24 has a recess 26, so located and of such length that when the cover is placed on the section 4 slightly to one side of its operative position thereon, with the rear recess 25 beginning to receive the upper section'lug 23, the cover may be brought down evenly against the upper section top rim, with the front lug 21 thereof passing up through this front recess 26 of the cover; and then, when the cover is swung intoits alined operative relation with the upper section. 4, its edge portion at one end of the recess 26 slips snugly under the lateral extension 22 of the upper section front lug 21, while the adjacent edge 27 of the recess 26 wedges against the back of this lug 21, wedging the cover 24 back so that the upper section rear lug 23 is snugly received in the rear recess 25 of the cover, as just before described. Preferably, this front edge portion of the cover is made consider ably thinner than the main part of the cover, to slip under the extension 22 and yet allow the top ofthis extension and of the lug. 21 that it is on, to lie even with the upper surface of the cover 24, as does the top of the rear lug 23. i

The sections 1 and 4 have recesses 28 and 29, respectively, in their meeting rims at upper section,

the rear, for escape of excess'plate material when the two are pressed together; and the cover 24 has the holes 30 through it, decreasing in diameter downwardly, into which portions of the molding material are extruded, forming dovetail attachments of the material to the cover; these being provisions similar to those well known in the art, as also is the mode of operation of the flask, which therefore needs no extended description. The cover first is secured on the then the mold material, such as plaster, is placed in the two sections, the plate material, such as hard rubber mass, together with the teeth, are placed in the mold, which has been formed inthe'two plaster sections, and then the flask sections are assembled, squeezed together'in a suitably powerful press, the fastening is completed by closing the catch 18, a-ndlthe flash treated in the vulcanizer to harden the rubber, usually with superheated steam.

As the plaster or other mold material, projectinginto the openings 29 of the cover 24 and hardening, strongly assists in holding the cover inp'lace, the fastening of the top cover need not be so very firm; that is, it is possible to have the cover slip very easily into and out of position, sofar as concerns the fastenings provided in the flask construction. During the vulcanization, the plaster or other 'mold material becomes somewhat softened so that the extruded portions thereof in the holes 29 will shear off by removal of the cover 24. The fastening of thesections 1 and 4 together, however; requires ample strength, whichvI have provided; this being possible especially owing to the very simple construction of the fastenings, permitting them to be amply large and strong, yet not increasing the over all dimensions of the flask so as to make it disproportionately large or heavy, and permitting itto go easily into the vulcanizer of the usual size in proportion to the size of the denture molded.

Modifications may occur in practice, and while I have somewhat specifically :illustrated and described my invention. I do not wish to beunderstood as being limited to such precise disclosure, but what I claim as new and desire to secure by Letters Patent 1s: 7

1. In a dental flask comprising separable sections, a hook on one section and means on the other section engaged by the'hook, a tapered extension on the one section, remote from said hook, and an extension on the other section having a tapered socket to receive said extension as the sections are swung together with said hook and its engagingmeans as a pivot. V

2. In a dental flask comprising separable sections, a hook on one section and means on the other section engaged by the hook, a

tapered extension on the other section, remote from said hook, a catch pivoted on the end of said extension, and an extension on the other section having a tapered socket with a slot in one side, to receive said extension as the sections are swung together with said hook and its engaging means as a pivot, said slot allowing passage of said catch with the catch in an open position, and said catch being adapted to be turned to engage under the extension of the other section, at one side of said slot.

3. In a dental flask comprising separable sections, a hook fastening for the two sections at one side of the flask, and a second fastening for the two sections at a remote side of the flask, comprising an extension having a tapered socket on one section, and a tapered extension on the other section to fit into said socket.

4. In a dental flask comprising separable sections, a hook fastening for the two sections at one side of the flask, and a second fastening for the two sections at a remote side of the flask, comprising an extension having a tapered socket on one section, a tapered extension on the other section to fit into said socket, and a catch pivoted on the end of said tapered extension to engage under the extension having the socket, this latter extension being slotted for passage of said catch through the socket while swung away from engaging position.

CONRAD FRITZENWALLNER. 

